Folder EXP:
Results from Raman scattering measurements performed in diamond anvil cells. Raman spectra were obtained at room temperature using an Alpha300M+ confocal microscope (Witec Gmbh). A 532 nm laser line was delivered to the microscope via a single-mode optical fiber, with the laser power at the sample not exceeding 30 mW. The Raman signal was collected through a 50× long working distance objective (NA = 0.40) and transmitted through a photonic-crystal fiber to a lens-based spectrometer (Witec UHTS 300, f/4 aperture, focal length 300 mm) equipped with a back-illuminated Andor iDUS 401 detector, which was thermoelectrically cooled to -60 °C. The spectra were acquired using a 1800 mm grating, resulting in a spectral resolution of 1.2 cm-1. The typical acquisition times ranged from 9 to 12 seconds with 10-15 accumulations. The collected spectra were post-processed using the Project FIVE software (Witec Gmbh) to perform background subtraction and cosmic-ray removal. Letters R1 – R4 mark consecutive experimental runs.
Description of files:
*.txt – normalized spectra obtained upon compression (Raman shift in first column, pressure given in the header of each column
*freq.dat – position of Raman bands obtained by fitting the Raman spectrum with with pseudo-Voigt profiles
Folder DFT:
Input files and results of Density Functional Theory (DFT) modelling (geometry optimization and Raman spectrum calculations) performed in CASTEP (version 21 and 22) for four polymorphs of NaZnF3 (GdFeO3-, CaIrO3, La2S3, and Sb2S3-type) at ambient and high pressure (up to 80 GPa) using the PBEsol functional. Data for each polymorph contained in a sperate folder, with pressure points in separate subfolders.
Calculation parameters: 1100 eV cutoff of the plane-wave basis set; norm-conserving pseudopotentials; SCF convergence: 10–7 eV per atom; k-point mesh with a 2π × 0.03Å−1 spacing.
Description of selected files:
*.cell - structural data and calculations parameters (pressure, pseudopotential, k-point sampling)
*.param - calculation parameters
*.castep - results file
